Comparison of Saccharomyces cerevisiae F-BAR Domain Structures Reveals a Conserved Inositol Phosphate Binding Site

• Published in: Structure (London) 2015-02, Vol.23 (2), p.352-363
• Main Authors: Moravcevic, Katarina, Alvarado, Diego, Schmitz, Karl R., Kenniston, Jon A., Mendrola, Jeannine M., Ferguson, Kathryn M., Lemmon, Mark A.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; BASIC BIOLOGICAL SCIENCES; Binding Sites - genetics; Crystallography, X-Ray; Green Fluorescent Proteins - metabolism; GTPase-Activating Proteins - chemistry; GTPase-Activating Proteins - genetics; GTPase-Activating Proteins - metabolism; HeLa Cells; Humans; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Inositol Phosphates - genetics; Inositol Phosphates - metabolism; Models, Molecular; Molecular Sequence Data; Protein Structure, Tertiary; Saccharomyces cerevisiae - chemistry; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins - chemistry; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Sequence Alignment; Species Specificity
• ISSN: 0969-2126; 1878-4186
• DOI: 10.1016/j.str.2014.12.009

F-BAR domains control membrane interactions in endocytosis, cytokinesis, and cell signaling. Although they are generally thought to bind curved membranes containing negatively charged phospholipids, numerous functional studies argue that differences in lipid-binding selectivities of F-BAR domains are functionally important. Here, we compare membrane-binding properties of the Saccharomyces cerevisiae F-BAR domains in vitro and in vivo. Whereas some F-BAR domains (such as Bzz1p and Hof1p F-BARs) bind equally well to all phospholipids, the F-BAR domain from the RhoGAP Rgd1p preferentially binds phosphoinositides. We determined X-ray crystal structures of F-BAR domains from Hof1p and Rgd1p, the latter bound to an inositol phosphate. The structures explain phospholipid-binding selectivity differences and reveal an F-BAR phosphoinositide binding site that is fully conserved in a mammalian RhoGAP called Gmip and is partly retained in certain other F-BAR domains. Our findings reveal previously unappreciated determinants of F-BAR domain lipid-binding specificity and provide a basis for its prediction from sequence. [Display omitted] •F-BAR domains differ in their phospholipid-binding specificity•The Saccharomyces cerevisiae Rgd1p F-BAR domain selectively binds phosphoinositides•Crystallography identifies a phosphoinositide binding site in Rgd1p F-BAR domain•This site is partly conserved in other F-BAR domains but fully in a human RhoGAP F-BAR domains are best known for binding curved membranes (and bending membranes). Moravcevic et al. show that yeast F-BAR domains also have distinct phospholipid-binding specificities. They use crystallography to identify a phosphoinositide binding site in the F-BAR domain from a RhoGAP, conserved in its human ortholog.